• Korean Journal of Food Science and Technology
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• v.50 no.6
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• pp.565-571
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• 2018

After adding eight different kinds of PAHs to soybean oil and perilla oil samples, changes of PAHs contents after activated carbon treatment with different conditions of activated carbon concentration, temperature, and time were investigated. PAHs contents decreased in both soybean oil and perilla oil with increasing activated carbon concentrations. Neither of the PAHs were detected in the soybean oil samples after the addition of only 0.05% of activated carbon, while the contents of most kinds of PAHs decreased below the limit of quantification in the perilla oil samples after the addition of up to 0.4% of activated carbon. PAHs contents decreased as the temperature of the activated carbon treatment increased, and most PAHs were not detected in the soybean oil samples at temperatures above $80^{\circ}C$. With regards to the activated carbon treatment time, the PAHs contents also decreased as the treatment time increased. In case of soybean oil, four kinds of PAHs were not detected after treatment with 0.05% of activated carbon at $70^{\circ}C$ for 10 min.

• Analytical Science and Technology
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• v.19 no.4
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• pp.285-289
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• 2006

In this study, the effect of an acidic treatment on granular activated carbon (GAC) and activated carbon fibers (ACF) was investigated for a $Pb^{2+}$ and $Ni^{2+}$ ion adsorption. 1.0 M nitric acid solution was used as the acid solution for the surface treatment. Surface properties of the GAC and ACF were characterized by the pH, elemental analysis and pHpzc (pH of the point of zero charge). Their specific surface area and the pore structure were also evaluated by the nitrogen adsorption data at 77K. As a result, the acidic treatment led to an increase of the oxygen-containing functional groups. Furthermore, the adsorption capacity of the acid-treated GAC and ACF was improved in the order of acidic-ACF > untreated-ACF > acidic-GAC > untreated-GAC, though the decrease in specific surface area induced by a pore blocking of the functional groups was observed.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.2
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• pp.20-27
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• 2016

Ethylene gas is a natural hormone that directly affects the freshness of agricultural products, so it is very important for the maintenance of freshness to remove ethylene gas from corrugated board boxes. Many methods for the removal of this and other gases have been reported. In this study, the utilization of an absorbent using activated carbon was adopted for the removal of ethylene gas from a corrugated board box. Activated carbon powders were prepared by grinding in a laboratory and were used to treat the surface and to laminate paperboards with a starch solution. The ethylene gas absorption was evaluated by using a gas chromatography to measure the residual ethylene gas concentration. About 60% of the ethylene gas was absorbed by the activated carbon itself. However, the paperboards that were surface-treated and laminated with starch and activated carbon showed lower than 20% ethylene gas absorption. This was because the starch and smaller particles of activated carbon blocked the surface pores of activated carbon particles. Therefore, either the use of the binders must be minimized for the surface treatment of paperboards, or activated carbon packs can be used as absorbents in corrugated boxes.

• Journal of Environmental Science International
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• v.2 no.1
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• pp.73-81
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• 1993

Adsorption process using granular activated carbon(GAC) has been considered as one of the most effective water treatment technologies to remove humic acid which is recon- niEed as trihalomethane(THM) precursor in chlorination. To design the most effective GAC process, it is necessary to conduct the test of adsor- ption performance by means of isothem, batch rate and column studies and to select the most effective activated carbon according to raw materials of GAC - lignite and coconut shell. The objective of this study is to investigate the adsorption performance of humid acid on two activated carbons - lignite activated carbon(LAC) and coconut shell activated car- bon(CAC) made in Korea. It is available to represent UV-abs and trihalomethane formation potential(THMFP) as concentration of humic acid due to good relationship. The adsorption capacity of humid acid is not concerned with surface area of activated carbon but with pore size related to about $100{\AA}$, and then LAC forming at the extent of mesopore is found to be eight times more effective in adsorption capacity than CAC forming at micropore. The adsorption capacity of LAC and CAC is better at pH 5.5 than at pH 7. Pore and surface diffusion coefficients calculated from the diffusion model are $7.61\times10^{-13}m^2/sec$, $3.52\times10^{-15}m^2/sec$ for CAC, and $3.38\times10^{-12}m^2$/sec and $Ds=1.48{\times}10^{-15}m^2/sec$ for GAC respectively. From the results of column test it shows that the performance of LAC is also better than CAC and the optimal EBCT(Empty Bed Contact Time) is 4.52min. and activated carbon removes selectively the components of humic acid to be easily formed to THM.

• Journal of Environmental Health Sciences
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• v.20 no.3
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• pp.1-12
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• 1994

Wastewaters being treated and final effluents were collected from 3 wastewater treatment plants of petrochemical industries, from August 31 to October 4, 1993 in an interval of 10 days, and further analysed by GC/FID to investigate discharge situation and removal efficiency on polycyclic aromatic hydrocarbons. The results were as follows: 1. The PAHs 294.57 $\mu$g/l were discharged in primary treatment effluent of plant A to manufacture vinyl acetate resin and acryl, and removed 54.51% by aeration and totally 84.71%. 2. The PAHs of the highest concentration were discharged in primary treatment effluent of plant B to manufacture PS resin and ABS resin, but removed 91.65% by activated sludge process and 98.19% by activated carbon to discharge PAHs of the lowest concentration comparing to another treatment operations. 3. The PAHs 99.96 $\mu$g/l of the lowest concentration were discharged in wastewater of plant C to manufacture epoxy resin, and removed 80.48% by activated sludge process. 4. B treatment system including activated carbon showed up the best removal efficiency of PAHs. Activated carbon therefore, seems to be effective as tertiary treatment. 5. Correlation coefficient of components to total PAHs was generally low, and correlation coefficients of phenanthrene, pyrene and acenaphthylene to total PAHs were each 0.98, 0.97 and 0.80, respectively. Correlation coefficient of the sum of phenanthrene, pyrene and acenaphthylene to total PAHs was 0.99, so that the sum of phenanthrene, pyrene and acenaphthylene was available as index to estimated total PAHs. 6. Phenanthrene and Chrysene were very well treated biologically and acenaphthylene and fluoranthene were untreated biologically. 7. Considering EPA standards, it seems that the concentration of phenanthrene, pyrene, fluoranthene, and benzo(k)fluoranthene is high level.

• Composites Research
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• v.35 no.1
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• pp.1-7
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• 2022

The activated carbon is a very good choice for using as supercapacitor electrode materials. Herein, the flower of Shorea robusta, a bio-waste material was successfully used to synthesize the activated carbons for application as supercapacitor electrode materials. The activated carbon was synthesized through chemical activation process followed by thermal treatment at 700℃ in presence of N₂ atmosphere using KOH, ZnCl₂ and H₃PO₄ as the activating agents. The physicochemical analyses demonstrate that the obtained activated carbons are graphitic in nature and the degree of disorder of the graphitic carbons is changed with the activating agents. The activated carbon obtained from Shorea robusta flower (ACSF-K) electrode shows the specific capacitance of ~610 F g^-1 at 2 A g^-1 current density, which is higher than ACSF-Z (560 F g^-1) and ACSF-H (470 F g^-1) electrode material under the identical current density. The synthesized graphitic carbons also demonstrated good rate capability and high electrochemical stability as supercapacitor electrode.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.2
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• pp.475-483
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• 2017

Geosmin and 2-methylisoborneol (2-MIB) produced by cyanobacteria during algal blooming in surface water are the major taste-and-odor-causing compounds in drinking water and need to be removed. Activated carbon is often used in treatment plants for the mitigation of odor problem. However, there is a lack of information on the effect of pore size distribution and particle size of activated carbon for adsorption of both odor compounds. Therefore, we studied the effect of pore size distribution and particle size of activated carbon on the adsorption of geosmin and 2-MIB. When comparing the adsorption of geosmin and 2-MIB between activated carbon fiber (ACF), powdered activated carbon (PAC) and granular activated carbon (GAC), the order of removal efficiency was PAC > ACF > GAC. As a result of comparing PACs with various pore distribution characteristics, well-developed micropores on activated carbon were found to be favorable for adsorption of geosmin and 2-MIB. For particle size, smaller was more effective for adsorption of geosmin and 2-MIB.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.1
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• pp.27-34
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• 2006

This study was conducted to evaluate the performance of a membrane bioreactor filled with high concentration of powdered activated carbon (HCPAC-MBR) to reduce DBPs at the drinking water treatment. The pilot system was installed after the rapid sand filtration process whose plant was the conventional treatment process. The removal efficiencies of DBPs were measured during pilot operation period of 2 years. HAA and THM removal rates could be maintained around 80~90% without any troubles and then tremendous reduction of HAA and THM reactivity were observed more than 52%. The average removal rate of HAA formation potential (FP) and THM formation potential (FP) were 70.5% and 67.6% respectively. It is clear that the PAC membrane bioreactor is highly applicable for advanced water treatment to control DBPs.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.1
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• pp.141-148
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• 2008

This study was conducted to evaluate the effect of PAC(Powder Activated Carbon) retention time on stable operation of high concentration powered activated carbon(HCPAC-MBR) in the treatment of secondary domestic wastewater. The pilot scale HCPAC-MBR system was operated at two different SRTs, 25 days and 100 days. The main drawback of HCPAC-MBR system was the rapid increase of trans-membrane pressure. The increase rate of trans-membrane pressure was proportional to SRT value at constant flux. This result seemed to be caused by reduced amount of EPS adsorbed on the PAC in the reactor by decreasing the SRT of the PAC. The particle size of the PAC was also influenced by SRT. The PAC size was decreased as SRT was increased. The change of particle size could be one reason for the change of trans-membrane pressure. The pore volume in the cake-layer formed on the membrane surface became to be increased by reducing SRT, because the cake-layer was highly composed of the PAC. Therefore, increased pore volume might play a role to reduce the trans-membrane pressure. The removal rate of E260 and TOC was also inversely proportional to SRT value.

• Journal of the Korea Concrete Institute
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• v.29 no.3
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• pp.283-290
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• 2017

Various types of fibers are utilized in cementitious materials in order to improve their performances. Here, the extent of fiber dispersion is of key importance regardless of the purpose of using fiber. In this study, activated carbon fiber dispersion in mortar samples was evaluated using electrical resistivity method. In particular, the extent of fiber dispersion was compared per mixing methods and surface treatments. The results suggest that the surface resistivity method is capable of evaluating dispersion of activated carbon fiber and that ultrasound dispersion method is superior to mortar mixer and hand mixer method. The use of superplasticizer improved dispersion but acid treatment was not effective.